1. Field of the Invention
The present invention relates to a magnetic recording/reproducing apparatus and more particularly, to a synchronizing signal detector for a magnetic recording/reproducing apparatus and a synchronizing signal detecting method thereof.
2. Discussion of the Related Art
A synchronizing signal detector for a magnetic recording/reproducing apparatus according to the background art will be described with reference to the accompanying drawings.
FIG. 1 is a block diagram illustrating a synchronizing signal detector for a magnetic recording/reproducing apparatus according to the background art. FIG. 2a is a timing chart illustrating waveforms of input data of FIG. 1. FIG. 2b is a timing chart illustrating output waveforms of a window signal generator of FIG. 1. FIG. 2c is a timing chart illustrating output waveforms of a signal generator of FIG. 1.
As shown in FIG. 1, the synchronizing signal detector for a magnetic recording/reproducing apparatus according to the background art includes a controller 11 for controlling the overall system, a window signal generator 12 for generating a window signal in response to a control signal of the controller 11, a shift register 13 for shifting externally input data, a comparator 15 for comparing its own synchronizing signal pattern with sequentially input data shifted by the shift register 13 as much as bits of the synchronizing signal pattern when the window signal of the window signal generator 12 is low and for outputting a certain signal if the synchronizing signal pattern is the same as the data, and a synchronizing signal generator 16 for generating a synchronizing signal in response to the signal output from the comparator.
The synchronizing signal pattern 14 is a synchronizing signal of a certain bit rate, having a pattern set to match the synchronizing signal of externally input data. The window signal is a reference signal for setting a synchronizing signal detecting block.
The operation of the synchronizing signal detector for a magnetic recording/reproducing apparatus will be described below.
If data is input as shown in FIG. 2a, the comparator 15 compares the synchronizing signal pattern 14 with data from the shift register 13 as much as the number of bits of the synchronizing signal pattern when the window signal output from the window generator 12 is low, as shown in FIG. 2b. Subsequently, if the same data as the synchronizing signal pattern is input, a certain signal is applied to the synchronizing signal generator 16 to generate the synchronizing signal, as shown in FIG. 2c.
The synchronizing signal detector for a magnetic recording/reproducing apparatus according to the background art has a problem. That is, as shown in FIG. 2c, high edge of a normal synchronizing signal is generated in "A" and "D" positions. However, the synchronizing signal is not generated as shown in "B" position or two high edges are generated as shown in "C" position due to data degradation, thereby causing data processing error.